Helcioniscus.} GASTROPODA. 85 



Subsp. Mestayerae, Suter, 1906. 



Helcioniscus Mestayerce, Sut., T.N.Z.I., xxxviii, 1905 (1906). 322, pi. 18, 

 f. 7-9. 



Shell solid, oval, slightly narrower in front, depressed conical. 

 Surface sculptured with numerous (about 50) broad depressed radiating 

 ribs, which are crossed by fine concentric striae. Colour dark olive, 

 with rather distant indistinct bluish-grey radiating bands. Apex 

 at about the front fourth, sharply pointed. Interior bluish-grey, 

 with a silvery lustre. There are at irregular intervals about 11 broad 

 radiating areas, with chestnut-coloured spots and patches, sometimes 

 arranged in divaricating pattern ; between these areas are several 

 radiating bands of an alternately darker and lighter grey colour. 

 These characters are very distinctly visible when the shell is held 

 up against the light, and give it a very beautiful appearance. The 

 central area is well defined ; the colour is reddish-orange, lighter near 

 the margin, finely and minutely dotted with yellow. The muscular 

 scar is about 3 mm. broad, but slightly impressed. 



Length, 49 mm. ; breadth, 39 mm. ; height, 14 mm. 



The dentition is unknown. 



Type in Miss Mestayer's collection. 



Hob. Stewart Island. 



5. Helcioniscus redimiculum, Reeve, 1854. Plate 7, fig. 20. 



Patella redimiculum, Bve., Conch. Icon. (1854), f. 50. Patinella redimi- 

 culum, Rve : Hutton, P.L.S. N.S.W., ix, 375. Helcioniscus redimi- 

 culum, Rve.. Man. Conch. (1), xiii, 136, pi. 23, f. 1, 2, 3, 5 ; Suter, 

 P. Mai. S., vi, 351. Patella redimiculum, Rve. : E. A. Smith, Ereb. & 

 Ter., ii, Moll., 4, pi. 1, f. 24. P. radians, Gmel., Conch. Icon., f. 25, 

 not of Gmelin. P. Pottsi, Hutton, C.M.M., 1873, 44. 



Shell elongate to round oval, depressed to conical. Sculptured 

 with 20 to 25 rounded, distant, and elevated radiate ribs, with a low 

 interstitial riblet, the whole surface ornamented with fine close con- 

 centric growth-lines, some of the growth-periods being usually strongly 

 marked. Colour of the ribs brown, lighter towards the margin, in- 

 tervals bluish-white ; having several darker concentric streaks, and 

 marked near the apex with oblique brown stripes. Very frequently 

 the colour is uniformly cinereous or brown, with the ribs more or less 

 darker. Apex at about the front fourth, but sometimes it is sub- 

 marginal ; inclined forward. Interior greyish to brownish-white, 

 strongly iridescent, more or less distinctly rayed with chestnut-brown ; 

 central area cream-white, bordered with olive behind, often light 

 brown or bluish-grey to light blue. Margin broadly denticulate. 



Length, 41 mm. ; breadth, 32 mm. ; height, 12 mm. Length, 

 49 mm. ; breadth, 40 mm. ; height, 20 mm. (specimen from Otago). 

 Length, 58 mm. ; breadth, 47 mm. ; height, 23 mm. (specimen from 

 Preservation Inlet). Length, 41 mm. ; breadth, 29 mm. ; height, 

 12 mm. (specimen from Bounty Islands). 



Dentition very much like that of H. denticulatus. 



